Arsenic is found in several allotropic forms and has both metallic and non-metallic properties. The grey metallic allotrope is a brittle, crystalline solid which tarnishes readily in air and burns in oxygen. It is resistant to attack by dilute acids and alkalis, but will react with hot acids and molten NaOH. Arsenic is poisonous (it is thought to h...Found on http://www.diracdelta.co.uk/science/source/a/r/arsenic/source.html

Arsenic: A metallic element that forms a number of poisonous compounds, arsenic is found in nature at low levels mostly in compounds with oxygen, chlorine, and sulfur. These are called inorganic arsenic compounds. Arsenic in plants and animals combines with carbon and hydrogen. This is called organic arsenic. Organic arsenic is usually less harmful...Found on http://www.medterms.com/script/main/art.asp?articlekey=14947

Ar·sen'ic adjective (Chemistry) Pertaining to, or derived from, arsenic; -- said of those compounds of arsenic in which this element has its highest equivalence; as, arsenic acid. Found on http://www.encyclo.co.uk/webster/A/124

1. <chemistry> One of the elements, a solid substance resembling a metal in its physical properties, but in its chemical relations ranking with the nonmetals. It is of a steel-gray colour and brilliant luster, though usually dull from tarnish. It is very brittle, and sublimes at 356 deg Fahrenheit. It is sometimes found native, but usually co...Found on http://www.encyclo.co.uk/local/20973

(As) (ahr-sen´ik) a chemical element, atomic number 33, atomic weight 74.92. It is toxic by inhalation or ingestion, and carcinogenic (see arsenic poisoning). In nature it occurs usually as one of its salts; in human environments it is often a pollutant in mining regions, and is used in dyes, hous...Found on http://www.encyclo.co.uk/local/21001

• (n.) Arsenious oxide or arsenious anhydride; -- called also arsenious acid, white arsenic, and ratsbane. • (a.) Pertaining to, or derived from, arsenic; -- said of those compounds of arsenic in which this element has its highest equivalence; as, arsenic acid. • (n.) One of the elements, a solid substance resembling a metal in its p...Found on http://thinkexist.com/dictionary/meaning/arsenic/

a chemical element in the nitrogen family (Group Va of the periodic table), existing in both gray and yellow crystalline forms. Although compounds of ... [13 related articles]Found on http://www.britannica.com/eb/a-z/a/105

(As) Type: Term Pronunciation: ar′sĕ-nik Definitions: 1. A metallic element, atomic no. 33, atomic wt. 74.92159; forms a number of poisonous compounds, some of which are used in medicine. 2. Denoting the element arsenic or one of its compounds, especially arsenic acid. Synonyms: arsenium, ratsbane &nb...Found on http://www.medilexicon.com/medicaldictionary.php?t=6396

(As) Massive native arsenic with quartz and calcite. Credit: Aram Dulyan & Wikipedia A toxic, semimetallic element of group VA of the periodic table. Compounds containing arsenic are used as a poison for rodents, insects, and weeds, and to harden lead and make semicon...Found on http://www.daviddarling.info/encyclopedia/A/arsenic.html

Arsenic is a trivalent and pentavalent, solid, poisonous common element usually found combined with metals as arsenides, the commonest of which is arsenical pyrites, FeAsS. It has a steel colour and high metallic lustre, and tarnishes on exposure to the air, first changing to yellow, and finally to black. In hardness it equals copper; it is extreme...Found on http://www.probertencyclopaedia.com/browse/HA.HTM

Semimetallic element (a metalloid), atomic number 33, relative atomic mass 74.92. Like phosphorus, the element can appear in different modifications, of which the grey, `metallic` arsenic is the most stable. Arsenic occurs in many ores and occasionally in its elemental state, and is widely distributed, being present in minute quantities i...Found on http://www.talktalk.co.uk/reference/encyclopaedia/hutchinson/m0009908.html

Arsenic is a chemical element with symbol As and atomic number 33. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250. Arsenic is a metalloid. It can exist in various allotropes, although only the gray form has important use in ind...Found on http://en.wikipedia.org/wiki/Arsenic